Buttonhole cutter for buttonhole sewing machines



1933. J. KIEWICZ 1,896,364

BUTTONHOLE CUTTER FOR BUTTONHOLE SEWING MACHINES Filed Feb. 5, 1929 3 Sheets-Sheet 1 John Kie'wic; byWwI/W A1Tys Feb. 7, 1933. J. KIEWICZ 1,896,364

BUTTONHOLE CUTTER FOR BUTTONHOLE SEWING MACHINES Filed Feb. 5, 1929 s Sheets-Sheet 2 Fig.2.

lnvenfor.

John Kiewic Y Afl'ys.

Feb. 7, 1933. J. KIEWICZ 1,896,364

BUTTONHOLE CUTTER FOR BUTTONHOLE SEWING MACHINES Filed Feb. 5, 1929 5 Sheets-Sheet 3 Fig.8..

lnvenTor.

Uohn Kiewic'g Anya.

Patented Feb. 7, 1933 UNITED STATES PATENT OFFICE JOHN KIEWICZ, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE REESE B'OTTON HOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE BUTTONHOLE CUT ER. FOR. BUTTONHOLE snwme MAcrrINEs Application filed February 5, 1929. Serial No. 337,676.

This invention relates to buttonhole sewing machines and particularly to the cutter for cutting the buttonhole slit. Buttonhole cutters usually comprise a cutting knife operating on one side of the work and acutting block on the other side of the work, the two being closed together to perform the buttonhole cutting operation. The member which is located above the work is usually mounted on a lever which is actuated at the proper time by a cam projection 011 the main cam of the machine.

In accordance with my invention the cutting element which is located below the work, is mounted for vertical movement, it normally occupying a lowered position during the stitching operation and it being given an upward vertical movement at the time thebuttonhole is to be cut. The features wherein the invention reside will be more fully hereinafter set forth and then pointed out in the appended claims. 7

In the drawings wherein I have shown a selected embodiment of the invention, Fig. 1 is a side view of a buttonhole sewing machine having my improved buttonhole cutting mechanism incorporated therein; 7

Fig. 2 is a top plan view of the lower member of the cutting couple;

Fig. 3 is a fragmentary view illustrating the posit-ion of the parts during the cutting of the buttonhole;

Fig. 4 is a section on the line 44, Fig. 1. The sewing machine herein shown is of that known type in which the work is clamped to a stationary bed frame and thestitch-forming mechanism is carried by a stitch frame which has a to-and-fro movement on the bed frame. In these buttonhole sewing machines the machine comes to rest at the end of the sewing operation with the stitch frame in buttonholecutting position and when the machine is started in operation the work clamps are closed onto the work, and if the machine is of the type which cuts the buttonhole befpre the stitching then the buttonhole cutter is actuated to cut the buttonhole slit. The stitch frame is then given a quick'movement from buttonhole cutting position to sewing position and the stitching on the buttonhole starts,said stitching being carried down one side of" the buttonhole and'back on the other side and during the stitching operation the stitch frame has aslow back and forth feeding movement. When the stitching on the buttonhole has been completedthe stitch.- forming mechanism comes to rest and the stitch frame is given a further quick or jump movement to bring it to buttonhole-cutting position thus completing the buttonhole cycle.

In. the drawings 1 indicates the bed frame provided with the usual clamp plates for supporting the work 20 and 2 indicates the usual work clamps by which'the work is clamped to the bed frame. The stitch frame carrying the stitch-forming mechanism is indicated generally at 3.

The stitch-forming mechanism herein shown comprises the usual upper needle 4 operating from above the work and a rotary turret 5 carrying the usual under thread mechanism and throat plate 6, said turret being rotatably mounted in bearings 7 8 carried by the depending portion'9 of the stitch frame all as usual in buttonhole sewing machines of this type. Inasmuch as the stitch-forming mechanism is of any well known'type I'have not thought it necessary to illustrate the under thread mechanism herein. g

The stitch frame carries the usual main cam 10 by which the stitching operations are controlled, and since the parts above described form no part of my present invention and their operation will be understood by those skilled in the artI have not thought it necessary to further illustrate them.

The buttonhole cutter, with which my present invention is concerned, includes the usual cutting couple which comprises a cutter and a cutting block. In the present embodiment of the inventionthe cutter, which is indicated at 11, is located below the woi'k and the cutter block, indicated at 12, is situated above the work. This cutter block 12 is shown as mounted on the usual cutter lever 13 pivoted at 14L to the stitch frame 3,

on the main cam 10 for giving the cutter lever 13 its cutting movement at the proper time in the cycle of operations.

In the present embodiment of the invention the cutter knife 11, which is located beneath the work, is mounted for vertical movement, it normally being in its lowered position shown in Fig. 1 but being adapted to move vertically into an operative buttonhole-cutting position shown in Fig. 3. One feature of the present invention relates to a construction wherein the power for moving the cutter knife 11 vertically is derived from the'cutter lever 13. In other words, the

means for raising the knife 11 is powered by the movement of the element carrying the cutter block. Any suitable means may be provided forgiving the cutter 11 its vertical movement at the proper time in the cycle of operations; I have herein shown for this purpose a wedge device which is actuated in proper timed relation with the other parts of the machine and by its movement operates to wedge or force the cutter 11 upwardly. This cutter is shown as carried by a block or support 17 which is mounted on a swinging frame 18, said frame having a forked construction and the arms thereof straddling the turret 5 and being pivoted at their front end to a bearing member 19 that is secured on the top of the upper turret bearing 7 The two arms 20 of the forked frame 18 are each shown as having a pointed pivot pin 21 rigid therewith which pins pivotin bearings 22 formed in the ends of the hearing block 19. When the cutting knife 11 is in its lowered position the frame 18 rests on the portion 23 of the stitch frame 3. 1 The actuating wedge by which the frame 18 is swung upwardly about its pivot 21 is indicated at 24.. This wedge slides back and forth upon the portion 23 of the frame 3 and is formed at its front end witha tapering or wedging surface 25 which engages a cooperating surface on the end of the frame 18.

lVhen the wedge 24 is moved to the left Fig. 1 or toward the bottom of the sheet in Fig. 2 it will wedge in between the portion 23 of the stitch frame 3 and the knifecarrying frame 18 and will raise said knifecarrying frame about the pivots 21 thus carrying the knife 11 upwardly from its inoperative position shown in Fig. 1 to its operative buttonhole-cutting position shown in Fig. 3, in which it is in engagement with the work.

The wedge member 24 is shown as being guided in its movement by guiding screws which are anchored in the portion 23 of the stitch frame 3 and operate'in slots 31 formed in the wedge member 24. 32 inclicates a spring acting on thewedge member and tending normally to hold it in its retracted or inoperative position.

This actuating wedge 24 may be operated by various means without departing from the invention. In the embodiment shown it is actuated by the movement of the cutter lever 13 although the invention is not limited to this particular way of actuating it.

The cutting lever 13 is shown as provided with a lateral projection or pin 26 which engages a wedge-actuating lever 27 pivoted at its upper end to the stitch frame as shown at 28 and the lower end 29 of which engages the wedge member 24:.

The construction is such that when the cutter lever 13 swings from'its inoperative position shown in Fig. 1 to its operative position shown in Fig. 3 the engagement of the projection 26 with the lever 27 will swing said lever forwardly and such forward movement will force the wedge member 2a forwardly into the position shown in Fig. 3 thereby rais ing the cutter knife 11 into its operative position againstthe work. The upward movement of the cutter 11, therefore, is coincident with the downward movement of the cutter block 12 and the two simultaneously engage opposite sides of the work and by their coaction serve to cut the buttonhole slit. In fact, movement of the cutter will preferably be such that it will not only engage the under side of the work but will be crowded up into the work to bring the cutting edge into a position substantially midway between the top and bottom faces of the work. Hence the cutting edge of the cutter 11 will meet the face of the cutting block l2 at a median point in the work. This is a considerable advantage in the case of thick cloth like overcoat material because it prevents any undue stretching of the upper face of the work as might occur if the cutting edge of the knife and the cutting face of the block met in the plane of the lower face of the work.

The cutting knife 11 may be of a size to cut a buttonhole of the maximum length. If it is desired to cut a buttonhole slit of a less length than this maximum length this may be done by employing a block 12 of the proper size. The blocks 12 are removably secured to the cutter lever 13 as usual so that they are interchangeable. If a knife of maximum length is used the actual length of the buttonhole slit will be governed by the length of the cutter block 12 because the cloth will be out only at the points where the cutting edge of the knife meets the cutting face of the block. If a short cutting block is used the buttonhole slit will extend from the eye forward to the end of the block 12 and the portion of the cutting edge of the knife 11 beyond the block will be ineffective so far as cutting a buttonhole slit is concerned. If, however, a longer block is employed then the buttonhole slit which is cut will be correconstructed to be readily removed from the lever 13. Said lever is shown as having a shouldered recess 33 to receive the block 12, said block being held in position against the shoulder of the recess by the spring-clamping member 34 and a steady pin 35 all as usual in buttonhole sewing machines.

I claim:

1. In a buttonhole sewing machine, the the combination with work-holding means, of a vertically-moving buttonhole-cutting knife beneath the work, a cutting block above the work movable toward and from the work, means to give the cutting block its operative movement, and a wedge device to raise the knife vertically into cutting relation with the block.

2. In a buttonhole sewing machine, the combination with work-holding means, of a vertically swinging frame situated beneath the work, a buttonhole cutter carried by said frame, a cutting block above the work, means to move the block into cutting position, and a wedge to swing the frame upwardly thereby to carry the knife into cutting relation with said block.

3. In a buttonhole sewing machine, the combination with work-holding means, of a vertically swinging frame beneath the workholding means, a buttonhole-cutting knife carried by said frame, a cutting block above the work, a cutting lever on which said block is mounted, means for actuating said lever, a wedge device for raising the frame, and means actuated by said lever to operate the wedge device thereby to carry the cutter into cutting relation with the block.

4. In a buttonhole sewing machine, the combination with work-holding means, of buttonhole-cutting mechanism comprising two co-operating cutting elements, one of which is located above the work and the other of which is below the work, the latter cutting element being vertically movable, a lever carrying the cutting element located above the work, a cam by which the operations of the machine are controlled, said cam having means to give said lever its buttonhole-cutting movement, and means actuated by said buttonhole-cutting movement of the lever to raise the vertically-movable cutting element into buttonhole-cutting position.

5. In a buttonhole sewing machine, the combination with work-holding means, of buttonhole-cutting mechanism comprising two co-operating cutting elements, one of which is located above the work and the other of which is below the work, the latter cutting element being vertically movable, a lever carrying the cuttingelement located above the work, a cam by which the operations ofthe machine are controlled, said cam having means to give said lever its buttonholecutting movement, a wedge for raising the vertically-movable cutting element, and

means actuated by said lever to give the wedge its operative movement.

In testimony whereof, I have signed my name to this specification.

JOHN KIEWICZ. 

